A user's online search experience may be enhanced through better understanding of the user's intent. Query tagging, the assigning of semantic labels to terms within a query (e.g., a user's search query), is one technique that may be utilized to determine the context of the query. The semantic labels assigned to terms within the query may be used to retrieve relevant information about the user's needs. For example, a phrase “digital camera” within a query may be labeled as a “product class”. The semantic label “product class” may be used to retrieve additional content (e.g., contextual advertisements relating to products) that may be presented to the user for an enhanced experience.